| Title | Thermal Infrared Remote Sensing of Geothermal Areas – Case Studies Involving the KrýsuvÃk and Hengill Geothermal Fields, Southwest Iceland |
|---|---|
| Authors | LucÃa Magali RAMÃREZ-GONZÃLEZ, Ingibjörg JÓNSDÓTTIR, Þorvaldur ÞÓRÃARSON |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | remote sensing, thermal infrared, Krysuvik, Hengill |
| Abstract | Thermal infrared (TIR) remote sensing provides a tool for mapping, quantifying and monitoring thermal anomalies associated with surface geothermal manifestations. Here we compare TIR imagery acquired by three different platforms: satellites, airborne and unmanned aerial vehicle (UAV). We selected two areas for our case studies: the KrýsuvÃk and the Hengill geothermal fields in Southwest Iceland. At KrýsuvÃk, the statistical analysis of the kinetic land surface temperature retrieved from nighttime satellite images of Landsat and ASTER, detected consistent spatial distribution of thermal anomalies within the active geothermal field. Airborne TIR-imagery enabled detailed mapping of thermal anomalies of low temperature contrast, and TIR images acquired by a camera on an UAV at different elevations were compared with ground measurements. The UAV-based TIR image taken at 30 m elevation was used to calculate radiative heat flux and the results give values that are on the same order of magnitude as the estimated heat flux from the on-the-ground soil measurements. The analysis of a 2002-2017 satellite-based time series detected extinct surface hydrothermal activity in the southwest, and a thermal anomaly possibly affected by crustal deformation in the southeast. At Hengill, the analysis of a satellite-based time series from 2002 to 2018 reveals patterns consistent with the known field mapped surface manifestations and also detected an area with new fumaroles, providing a target for an UAV survey. This study demonstrates that the combination of TIR data of different spatial resolution supports long-term monitoring of geothermal systems providing time-space information of the surface geothermal manifestations. |